Although wheat is generally known as a health promoting cereal grain providing an important contribution to daily energy intake worldwide, it has been reported to elicit adverse physical reactions (e.g. coeliac disease, wheat allergy) in susceptible individuals. Coeliac disease is a severe inflammatory disorder of the small intestine partly caused by dietary gluten sensitivity, with a prevalence of 0.5-1%. On the other hand, there is a large proportion of the general population (0.5-30%) who avoid or reduce gluten-containing products despite the fact that coeliac diseases, allergy or any related autoimmune involvement have been ruled out. This phenomenon is referred to as non-celiac gluten sensitivity (NCGS) or non-celiac wheat sensitivity (NCWS) and manifests as gastrointestinal (e.g. abdominal discomfort, bloating, diarrhea, rumbling, pain) and/or extra-intestinal complaints (e.g. headache, lethargy, depression, anxiety) after consuming wheat or gluten, which improve after gluten/wheat withdrawal.

The biological rationale potentially leading to symptoms in non-coeliac gluten or wheat sensitivity is not clear, and the phenomenon may also be affected by psychosocial factors, in part fueled by articles in the lay press and social media. Information is emerging that gluten-containing products can cause medical and psychological symptoms, with a link to the belief that our body has not had sufficiently evolved to adapt to grains in our diet. As a consequence, more and more people embrace a gluten-free diet. However, studies examining the contribution of consumer perceptions in symptom development are scarce. Therefore, a study is planned to study the impact of psychosocial factors on symptom development when consuming bread in subjects with self-reported non-celiac gluten sensitivity.

This study will independently run at two sites: 1) Netherlands, Lead Dr Daisy Jonkers, Dept. of Internal Medicine, Maastricht University Medical Center and Prof Dr CR Markus, Maastricht University; Faculty of Psychology and Neuroscience; Dept of Neuropsychology & Psychopharmacology; Maastricht, The Netherlands 2) United Kingdom, Lead Prof Dr L Dye, and Dr Clare Lawton, Human Appetite Research Unit; School of Psychology, University of Leeds, UK